It is known that 2 molecules of acrylonitrile can be added to aryl substituted acetonitriles. As described by Bruson and Reiner in J.Amer.Chem.Soc. 64. 2850 (1942) and U.S. Pat. No. 2,305,529, the reaction proceeds smoothly and in high yields to trinitrile compounds of the general formula ##STR1##
It is also known from a publication by Badger et al. in J.Chem.Soc. 1949, 1141-4, that hydrogenation of such trinitrile compounds may lead to cyclized products or decomposition products, e.g. 3-phenyl-piperidine, ammonia and other, unidentified high melting basic compounds.
U.S. Pat. No. 3,661,918, however, describes the formation of a bicyclic tertiary amine compound of the formula ##STR2## which is obtained from the above phenyl substituted trinitrile compound by varying the hydrogenation conditions.
All the above mentioned hydrogenation products are thus either secondary or tertiary amines.
The amino compounds mentioned above are not suitable for the production of high molecular weight synthetic resins by the isocyanate addition process which mainly requires difunctional components.
It has now surprisingly been found that the above mentioned trinitriles can be hydrogenated in such a way that new diamines are obtained in high yields. These new diamines still contain an unchanged nitrile group. Because of the presence of this nitrile group, the new diamines are suitable for the production of nitrile-containing polyurethane ureas or polyureas by the isocyanate polyaddition process. The nitrile-containing polyaddition products obtained using the new diamines as chain lengthening agents are distinguished by numerous remarkably advantageous properties, in particular their excellent adherence to a variety of substrates and their exceptional oil resistance.